JP2859766B2 - Magnetic head drive circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head drive circuit used in a magneto-optical recording apparatus of a magnetic field modulation system.

[0002]

2. Description of the Related Art A magneto-optical recording apparatus irradiates a recording medium with a laser beam to raise the temperature of a perpendicular magnetic film. Information is recorded by magnetizing in the direction. The recording method includes an optical modulation method for changing a laser beam according to a recording signal and a magnetic field modulation method for changing an external magnetic field. In the light modulation method, a DC external magnetic field is applied to a recording medium, and a laser beam modulated by a recording signal is applied to the recording medium, so that only a portion irradiated with high-energy laser light is magnetized in the direction of the external magnetic field. It is to let. In the magnetic field modulation method, a recording medium is irradiated with a uniform high-energy laser beam, and an external magnetic field modulated by a recording signal is applied thereto.
The portion irradiated with the laser beam is magnetized in a direction corresponding to the external magnetic field at that time.

Here, in the light modulation method, when rewriting an already recorded area on a recording medium with other information,
Before that, the initialization must be performed once, and there is a disadvantage that the access speed is reduced. On the other hand, in the magnetic field modulation method, the entire rewriting area irradiated with the laser beam is magnetized in the direction of the external magnetic field, so that another information can be directly overwritten (overwritten). Therefore, from the viewpoint of improving the access speed, this magnetic field modulation method has been widely adopted at present. However, in the magnetic field modulation method,
It is necessary to reverse the external magnetic field at high speed in accordance with the recording signal. Therefore, conventionally, the inductance of the head coil is made as small as possible by bringing the magnetic head close to the recording medium, and the inductance of the head coil is made smaller than that of the head coil as in the magnetic head drive circuit described in Japanese Patent Application Laid-Open No. 63-94406. However, a sufficiently large auxiliary coil is used to assist the reversal of the magnetic field of the head coil.

That is, as shown in FIG. 7, the magnetic head driving circuit includes a first current path 31 and a second current path 31 in response to a recording signal S.
The main switches 33 and 34 of the current path 32 are alternately turned ON / OF.
F. Therefore, when the main switch 33 of the first current path 31 is ON, the recording current I _X flows into the head coil 39 via a resistor R ₁₂ and the auxiliary coil 36 from the current source 38 of the second current path 32, the when the main switch 34 of the second current path 32 is oN, the recording current I _X in the reverse direction flows through the head coil 39 via a resistor R ₁₁ and the auxiliary coil 35 from the current source 37 of the first current path 31. Then, the head coil 39 can generate an external magnetic field according to the recording signal S. Further, when the main switch 33 of the first current path 31 is ON, the auxiliary coil 35 current I _L1 from the current source 37 of the first current path 31 through a resistor R ₁₁
The flow, when the main switch 34 of the second current path 32 is ON, through the auxiliary coil 36 current I _L2 from the current source 38 of the second current path 32 through a resistor R _12. Then, the auxiliary coils 35 and 36, while the recording current I _X of the head coil 39 and the other auxiliary coil 36, 35 is supplied to each other, is charged by the current I _L1, I _L2 (electromagnetic energy is accumulated ). For this reason, when the recording signal S is inverted and the main switches 33 and 34 are switched ON / OFF, the inductance of the auxiliary coils 35 and 36 on the side which has been charged by the current I _L1 or I _L2 up to that time. Since current is supplied to the small head coil 39,
The recording current _IX of the head coil 39 can also be reversed at a high speed.

In the magnetic head drive circuit shown in FIG. 7, while the main switch 33 or 34 is ON, the auxiliary coil 35 or 3 on the same first current path 31 or second current path 32 side.
6 is disadvantageous in that the currents I _L1 and I _L2 only for charging continue to flow, so that power is wasted too much. Therefore, in the magnetic head drive circuit described in JP-A-63-244402, as shown in FIG. 8, auxiliary switches 41 and 42 are provided for each of the auxiliary coils 35 and 36, and one of the main switches is provided. The auxiliary switch 42 or 41 on the side of the second current path 32 or the first current path 31 is turned ON only shortly before the switch 33 or 34 is turned ON and until the main switch 33 or 34 is turned OFF. Was so controlled.

That is, for example, when the main switch 33 of the first current path 31 is turned ON, only the auxiliary switch 42 of the second current path 32 is ON, and the auxiliary switch 41 of the same first current path 31 is OFF. Therefore, the current _IL1 does not flow through the auxiliary coil 35. However, when the recording signal S is inverted, the auxiliary switch 41 is also turned on, and the current I _L1 starts to flow to the auxiliary coil 35 through the main switch 33 which remains in the ON state, and charging is performed. After that, the recording signal S delayed by the delay circuit 40 is also inverted, and the main switch 33 is turned off and the main switch 34 is turned on. When the main switch 34 is turned on, the charged current from the auxiliary coil 35 is supplied to the head coil 39. Therefore, the recording current _IX can also be inverted at a high speed. Therefore, the current I _L1 is turned on by the main switch 33
By adjusting the delay time of the delay circuit 40 instead of continuing to flow during the time required for charging the auxiliary coil 35, wasteful consumption of power can be reduced. Also, the second current path 32
Similarly, when the main switch 34 is switched from ON to OFF, the current _IL2 can be prevented from flowing wastefully.

[0007]

However, even in the magnetic head drive circuit shown in FIG. 7, the auxiliary coils 35 and 36 are not charged at all at the start of recording. Therefore, at the start of this recording, these auxiliary coils 3
The high inductance of 5 and 36 hinders, and it takes a long time for the recording current _IX of the head coil 35 to reach a sufficient magnitude. That is, for example, when the main switch 33 of the first current path 31 is first turned ON at the start of recording, the time is determined by the resistance value of the resistor R ₁₂ of the second current path 32 and the inductance of the auxiliary coil 36 and the head coil 39. Due to the transient response based on the constant τ, it takes several μsec to several tens μsec for the recording current _IX supplied from the current source 38 to the head coil 39 to be sufficiently large.

Therefore, the conventional magnetic head drive circuit shown in FIG. 7 has a problem that data recorded at the start of recording tends to be unstable due to a shortage of a magnetic field from the head coil 39.

Also, in the magnetic head drive circuit shown in FIG. 8, currents I _L1 and I _L2 flowing through the auxiliary coils 35 and 36 during the delay time of the delay circuit 40 pass through the head coil 39. Since it is discarded as it is, power consumption is not wasted. In addition, if the information recording rate is further improved, the time during which the main switches 33 and 34 are turned on is further shortened.
_L1 and I _L2 have to be flowed, and FIG.
In this case, the same waste of power consumption occurs.

Therefore, in the case of the conventional magnetic head drive circuit shown in FIG. 8, since the two auxiliary coils 35 and 36 need to be charged completely separately, the disadvantage that power consumption is wasted is completely eliminated. There was a problem that it did not reach to resolve.

In view of the above circumstances, the present invention provides a magnetic head drive capable of generating a sufficient magnetic field from a head coil even at the start of recording to perform stable recording and completely eliminating unnecessary power consumption by an auxiliary coil. It is intended to provide a circuit.

[0012]

According to the magnetic head drive circuit of the present invention, a first current path and a second current path in which at least an auxiliary coil and a main switch circuit are respectively connected in series to a current source are provided in parallel. And the auxiliary coil and the main switch circuit in the first current path and the second current path are mutually connected via a head coil, and
A magnetic head drive circuit provided with main switch control means for alternately turning on / off a main switch circuit of a current path and a second current path in response to a recording signal, wherein the first and second main paths are controlled at a predetermined time before the start of recording. An idling means for turning on both the main switch circuits of the current path and the second current path;
The switch control means and the idling means are each independent.
It is configured to operate the main switch circuit at first ,
Thereby, the above object is achieved. In addition, the present invention
The magnetic head drive circuit at least assists the current source
The coil and main switch circuit are connected in series, respectively.
A first current path and a second current path are provided in parallel, and
The auxiliary coil and the main switch in the first current path and the second current path
Switch circuit is connected to each other via a head coil.
And the main switch circuit of the first current path and the second current path.
Main switch that turns ON / OFF the path alternately according to the recording signal
A magnetic head drive circuit provided with a switch control means,
At a predetermined time before the start of recording, the first current path and the second
Idling that turns on the main switch circuit of the flow path alternately
Means for achieving the above objectives.
You.

In the magnetic head drive circuit according to the present invention, a first current path and a second current path in which at least an auxiliary coil, an auxiliary switch circuit, and a main switch circuit are respectively connected in series to a current source are provided in parallel. And a series connection of the auxiliary coil and the auxiliary switch circuit in the first current path and the second current path and the main switch circuit are mutually connected via a head coil, and a main switch of the first current path is provided. A magnetic head provided with a switch control circuit for alternately turning on / off a circuit and an auxiliary switch circuit of a second current path, a main switch circuit of a second current path, and an auxiliary switch circuit of a first current path according to a recording signal. a drive circuit, said first current path and the auxiliary coil of the second current path, both wound on a common magnetic core, and are wound in a direction in which the direction of the magnetic flux in the magnetic heart matches Ri, head coil in accordance with a recording signal
Is configured to invert the current supplied to the
This achieves the above object.

[0014]

According to the configuration of the magnetic head drive circuit of the present invention,
The idling means turns on both the main switch circuits of the first current path and the second current path for a predetermined time before the start of recording by the magnetic head drive circuit. Then, current flows through the auxiliary coils of the first current path and the second current path, respectively, and charging is performed, so that the recording current of the head coil does not run short at the start of recording.

In this case, if the potentials between the auxiliary coil and the main switch circuit in the first current path and the second current path are different, current also flows in the head coil. Therefore, if the recording medium is affected when the head coil generates a magnetic field before the start of recording, it is necessary to make the impedance of the first current path and the second current path by the auxiliary coil and the like equal. . However, when the recording medium is not affected by the magnetic field from the head coil unless the laser beam is irradiated, as in a magneto-optical recording apparatus of the magnetic field modulation type, the idling means alternately turns on / off the main switch circuit. This does not cause a problem. Further, the main switch control means and the idling means
However, the configuration that operates the main switch circuit independently
Have been. Therefore, the recording operation control signal and idle
Recording operation even if the timing of the
It is possible to do.

According to another configuration of the magnetic head driving circuit of the present invention, when a current flows through the auxiliary coils of the first current path and the second current path, a magnetic flux in the same direction is generated in the common magnetic core. Therefore, regardless of whether the current flows through the auxiliary coil of either the first current path or the second current path, electromagnetic energy of the same polarity is accumulated in the common magnetic core, and both auxiliary coils are charged. Will be.

For this reason, even when the switch control circuit prevents the current from flowing through the auxiliary coil and the head coil of one of the current paths and the current from flowing through the auxiliary coil of the other current path, the other current path does not flow. When the ON / OFF switching is performed by the recording signal, the auxiliary coil in the other current path can sufficiently supply the recording current to the head coil. In addition, the switch control circuit cuts off the auxiliary coil of the other current path when energizing the auxiliary coil of one current path, so that current for charging only does not flow and wasteful power is not consumed. Do not consume.

The present invention can be generally applied to a magnetic recording apparatus that performs magnetic recording on a recording medium by changing a magnetic field, such as a magneto-optical recording apparatus of a magnetic field modulation system. Further, the magnetic recording device referred to here also includes a recording device of a magnetic recording / reproducing device.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

FIG. 1 shows a first embodiment of the present invention. This embodiment is a magnetic head drive circuit generally applied to a magnetic recording apparatus. A first current path 1 and a second current path 2 are connected to the power supply terminal 10 in parallel. The first current path 1, the current source 7, a resistor R _1, the auxiliary coils 5 and the main switch 3 is a circuit connected in series. The second current path 2 is a circuit in which a current source 8, a resistor R ₂ , an auxiliary coil 6, and a main switch 4 are connected in series. A head coil 9 is connected between a connection point between the auxiliary coil 5 and the main switch 3 in the first current path 1 and a connection point between the auxiliary coil 6 and the main switch 4 in the second current path 2. .

The head coil 9 is a coil for generating an external magnetic field of the magnetic head, and performs magnetic recording on a recording medium. Resistors R _1, R ₂ is for adjusting the level of the recording current I _X flowing into the head coil 9. The auxiliary coils 5 and 6 are charging (electromagnetic energy storage) coils having sufficiently higher inductance than the head coil 9. In addition, since the resistance of the auxiliary coils 5 and 6 is less than 1Ω, they are negligible with respect to the resistance values of the resistances R ₁ and R ₂ of 10Ω or more. The first current path 1 and the second current path 2 have the same resistance value of the resistors R ₁ and R ₂ ,
Since the inductances of the auxiliary coil 5 and the auxiliary coil 6 are also the same, their impedances are also equal.

Each of the main switches 3 and 4 of the first current path 1 and the second current path 2 is a switch circuit that is turned on when the control terminal goes to H level, and is composed of a MOSFET or the like. The recording signal S input to the magnetic head drive circuit of the present embodiment is supplied to the AND gate 22 and the OR gate 23.
, And sent to the control terminal of the main switch 3, inverted by the inverter 21 and then AND gate 24 and O
The signal is sent to the control terminal of the main switch 4 via the R gate 25. These AND gates 22, 24 adapted to be gated by the recording operation control signal C _1. Therefore, when the recording operation control signal C ₁ is at L level,
Regardless of the recording signal S, these AND gates 22, 2
4 is also always at the L level, and the main switches 3 and 4 are both turned off. Controller (not shown), only when the recording operation is performed by the magnetic head driving circuit, the recording operation control signal C ₁ and H level. Also, an OR gate 23,
25 is adapted to be gated by the idling control signal C _2. Therefore, the idling control signal C
_{When 2} is at the H level, the outputs of these OR gates 23 and 25 are always at the H level regardless of the recording signal S, and both the main switches 3 and 4 are turned ON. The control unit is a predetermined time before the start of the recording by the magnetic head driving circuit, to the idling control signal C ₂ to the H level.

The operation of the magnetic head drive circuit having the above configuration will be described.

[0024] When attempting to start a recording operation, as shown in FIG. 2, performs the idling operation control unit by the first idling control signal C ₂ before its H level.
Then, the main switch 3 of the first current path 1 and the second current path 2,
4 are both ON, currents I _L1 and I _L2 flow through the auxiliary coils 5 and 6, respectively. The currents I _L1 and I _L2 gradually begin to flow according to the transient response based on the time constant τ due to the resistance values of the resistors R ₁ and R ₂ and the inductance of the auxiliary coils 5 and 6, respectively. Since the idling operation is performed for a time equal to or longer than the time constant τ, the currents I _L1 and I _L2 reach a predetermined magnitude during this time, and the auxiliary coils 5 and 6 are sufficiently charged. During this idling operation, since the impedance of the first current path 1 and the impedance of the second current path 2 are equal, the recording current _IX does not flow through the head coil 9 and no external magnetic field is generated, so that any magnetic recording medium can be used. Has no effect.

When the idling period is over, a recording operation is started, and the control unit changes the idling control signal C ₂ to L level.
Together back to level, the recording operation control signal C ₁ to H level. Then, the H / L level of the recording signal S is directly input to the control terminal of the main switch 3, and the H / L level of the recording signal S is inverted and input to the control terminal of the main switch 4. , These main switches 3, 4
Turns ON / OFF alternately according to the recording signal S. Thus, for example, when the main switch 3 is turned ON the main switch 4 is turned OFF, the recording current I _X to the head coil 9 through a resistor R ₂ and the auxiliary coil 6 from the second current path 2 of the current source 8 When the main switch 3 is turned off and the main switch 4 is turned on, the first current path 1
The recording current _IX flows in the opposite direction from the current source 7 to the head coil 9 via the resistor R ₁ and the auxiliary coil 5. And
As a result, an external magnetic field corresponding to the recording signal S is generated from the magnetic head. When the main switch 3 is ON,
Current I _L1 flows in the auxiliary coil 5 via a resistor R ₁ from the first current path 1 of the current source 7, when the main switch 4 is ON, the resistor R ₂ from the second current path 2 of the current source 8 The current _IL2 flows through the auxiliary coil 6 via the auxiliary coil 6. Then, the auxiliary coils 5 and 6 are charged while the recording current _IX is not supplied to the head coil 9. Therefore, when the recording signal S is switched is ON / OFF of the main switch 3 and 4 is inverted, the recording current I _X of the head coil 9 is also to be inverted at a high speed. Also, at the start of recording, since the auxiliary coils 5 and 6 by the previous idling operation has already been charged, the recording current I _X of the head coil 9 is allowed to flow large enough from the start.

As a result, according to the magnetic head drive circuit of this embodiment, the auxiliary coils 5 and 6 can be charged without affecting any type of magnetic recording medium during idling operation. it recording current I _X flowing into the head coil 9 at the start of recording is such that insufficient eliminated.

FIG. 3 shows a second embodiment of the present invention. Note that components having the same functions as those of the first embodiment shown in FIG. This is the same in a third embodiment described later. This embodiment is a magnetic head drive circuit used in a magneto-optical recording device of a magnetic field modulation system. The configuration of the first current path 1 and the second current path 2 connected in parallel to the power supply terminal 10 is the same as that of the first embodiment shown in FIG. The circuit for inputting the recording signal S to the control terminals of the main switches 3 and 4 is substantially the same. However, FIG.
This idling control signal C ₂ in the first embodiment have OR gates 23, 25 is removed to the gate of, the same as if a substantially idle control signal C ₂ always fixed at L level.

The operation of the magnetic head drive circuit having the above configuration will be described.

When the recording operation is to be started, as shown in FIG. 4, an idling operation is performed for a predetermined time before that. The idling operation is the recording operation control signal C ₁ in a state where the control unit is not irradiated with the laser beam to the recording medium while the H level, carried out by feeding the recording signal S for an idling operation. It is assumed that the recording signal S for the idling operation repeats the shortest cycle inversion operation of the actual recording signal S. Therefore, when the recording signal S for the idling operation is sent to the magnetic head drive circuit, the main switches 3 and 4 of the first current path 1 and the second current path 2 repeat alternate ON / OFF, and the auxiliary coil 5 or While the recording current IX flowing through the head coil 9 via the auxiliary coil 6 is reversed, its absolute value is gradually increased. Then, when the idling operation is continued for a predetermined time, the charging of the auxiliary coils 5 and 6 is also completed, and the recording signal _IX can be inverted with a sufficient magnitude at high speed. Here, according to the experiment, the predetermined time for performing the idling operation is appropriately about 1.5 times the time constant τ described in the first embodiment. Although the external magnetic field from the magnetic head by the recording current I _X flowing into the head coil 9 even during the idling operation will occur, the magneto-optical recording medium,
If irradiation with high-energy laser light is not performed, it is not affected by this.

When the idling period ends, the recording operation starts. This recording operation, together with laser light with high energy is irradiated with the designated area of the magneto-optical recording medium in the order, the recording operation control signal C ₁ of the actual recording signal S remains H level is maintained magnetic head drive Input to the circuit. Then, as in the case of the first embodiment, the main switches 3 and 4 are alternately turned ON / OF according to the actual recording signal S.
Now perform F, external magnetic field is generated from the magnetic head by the recording current I _X flowing into the head coil 9. Then, the portion of the magneto-optical recording medium irradiated with the laser beam is sequentially magnetized according to the direction of the external magnetic field, and recording is performed. At this time, since the auxiliary coils 5 and 6 by the idling operation has already been completed charging, the recording current I _X of the head coil 9 at the start of recording is sufficiently large, so that it can be reversed at high speed Become.

[0031] Consequently, according to the magnetic head drive circuit of this embodiment, so that it takes a long time idling operation than in the first embodiment, without using the idling control signal C _2, when recording starts Shortage of the recording current _IX can be prevented.

FIG. 5 shows a third embodiment of the present invention. In the present embodiment, the configuration of the first current path 1 and the second current path 2 connected in parallel to the power supply terminal 10 is almost the same as that of the first embodiment shown in FIG. However, between the current source 7 and the resistor R ₁ and between the current source 8 and the resistor R ₂ , auxiliary switches 11 and 12 having the same configuration as the main switches 3 and 4 are added. The auxiliary coils 5 and 6, as well as the magnetic core 5a in common, the magnetic core 5a by the current I _L1, I _L2
Each coil is wound so that a magnetic flux in the same direction is generated in the coil. The configuration of the circuit for inputting the recording signal S to the control terminals of the main switches 3 and 4 is almost the same as that of the first embodiment, but the signal input to the control terminal of the main switch 3 in the first current path 1 is The second current path 2 is also input to the control terminal of the auxiliary switch 12 in the second current path 2.
The signal input to the control terminal of the main switch 4 is also input to the control terminal of the auxiliary switch 11 in the first current path 1.

The operation of the magnetic head drive circuit having the above configuration will be described with reference to FIG.

At the time of the recording operation, for example, when the recording signal S is at the H level, the main switch 3 of the first current path 1 and the auxiliary switch 12 of the second current path 2 are turned on, and the main switch 3 of the second current path 2 is turned on. Switch 4 and auxiliary switch 11 of first current path 1
Becomes OFF. Therefore, the auxiliary coil 5 of the first current path 1
Is not the current I _L1 flows, only the current I _L2 in the second auxiliary coil 6 of the current path 2 flows, which is the recording current I _X of the head coil 9 in. Further, when the recording signal S is at the L level, the main switch 4 and the auxiliary switch 11 is turned ON, since the main switch 3 and the auxiliary switch 12 is OFF, no current flows I _L2 in the auxiliary coil 6, the auxiliary The current I _L1 flows only through the coil 5 and this is the recording current I
It flows in the opposite direction as _X. Therefore, an external magnetic field corresponding to the recording signal S is generated from the magnetic head, and thus magnetic recording can be performed.

For example, when the recording signal S is changed from H level to L level.
When the level is inverted to the level, since the electromagnetic energy is stored in the common magnetic core 5a by the current I _L2 that has been flowing through the auxiliary coil 6, the auxiliary coil 5 has not passed the current I _L1 until immediately before. Despite the magnetic core 5a
The recording current I to the head coil 9 based on the electromagnetic energy of
Supply _X. Then, even when the recording signal S is reversed in the reverse direction, the auxiliary coil 6 supplies the recording current I to the head coil 9.
Supply _X. Therefore, when the recording signal S is reversed, the recording current I _X of the head coil 9 can also be reversed at high speed accordingly. In addition, since the currents I _L1 and I _L2 flowing through the auxiliary coils 5 and 6 all become the recording current I _X of the head coil 9, wasteful power consumption can be completely eliminated.

[0036] Consequently, according to the magnetic head drive circuit of the present embodiment, without damaging the recording current I _X of the head coil 9 functions to speed reversal, the current I of the auxiliary coils 5 and 6
_Unnecessary power consumption due to _L1 and I _L2 can be completely prevented.

In this embodiment, since the currents I _L1 and I _L2 do not flow through the auxiliary coils 5 and 6 in advance, the recording is started in the same manner as the conventional magnetic head driving circuit shown in FIG. There is a problem that the recording current _IX is insufficient. However, this problem can be solved by combining this embodiment with the configuration of the first or second embodiment and performing an idling operation at the start of recording.

[0038]

As is apparent from the above description, according to the magnetic head drive circuit of the present invention, the recording current of the head coil does not become insufficient at the start of recording.
Data can be reliably recorded. Ma
The main switch control means and the idling means
The main switch circuit operates independently.
Therefore, the recording operation control signal and the idling control signal
The recording operation can be performed even if the
You.

Further, according to another magnetic head drive circuit of the present invention, since it is not necessary to supply an unnecessary current by making the magnetic core of the auxiliary coil common, it is possible to completely eliminate waste of power consumption.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the first embodiment of the present invention.

FIG. 3 is a block diagram of a second embodiment of the present invention.

FIG. 4 is a time chart showing the operation of the second embodiment of the present invention.

FIG. 5 is a block diagram of a third embodiment of the present invention.

FIG. 6 is a time chart showing the operation of the third embodiment of the present invention.

FIG. 7 is a circuit block diagram of a conventional magnetic head drive circuit.

FIG. 8 is a circuit block diagram of another conventional magnetic head drive circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st current path 2 2nd current path 3 main switch 4 main switch 5 auxiliary coil 5a magnetic core 6 auxiliary coil 7 current source 8 current source 9 head coil 11 auxiliary switch 12 auxiliary switch

Claims (3)

(57) [Claims] A first current path and a second current path each having at least an auxiliary coil and a main switch circuit connected in series to a current source are provided in parallel, and the first current path and the second current path are provided. Between the auxiliary coil and the main switch circuit through a head coil, and
A magnetic switch drive circuit provided with main switch control means for alternately turning on / off the main switch circuits of the first current path and the second current path in accordance with a recording signal; And idling means for turning on the main switch circuits of both the first current path and the second current path for a predetermined time, wherein the main switch control means and the idling means comprise:
A magnetic head drive circuit configured to operate the main switch circuit independently . 2. A current source having at least an auxiliary coil.
A first current path in which main switch circuits are respectively connected in series
And a second current path are provided in parallel.
Coil and main switch circuit in the first and second current paths
Are connected to each other via a head coil, and
The main switch circuits of the first current path and the second current path are recorded and transmitted.
Main switch control means that turns on and off alternately according to the signal
Is a magnetic head drive circuit provided with At a predetermined time before the start of recording, the first current path and the second
Idling that turns on the main switch circuit of the flow path alternately
Magnetic head drive circuit comprising means. 3. A first current path and a second current path each having at least an auxiliary coil, an auxiliary switch circuit, and a main switch circuit connected in series to a current source, and the first current path and the second current path are connected in parallel. The series circuit of the auxiliary coil and the auxiliary switch circuit and the main switch circuit in the second current path are mutually connected via a head coil, and
The main switch circuit of the current path and the auxiliary switch circuit of the second current path, and the main switch circuit of the second current path and the auxiliary switch circuit of the first current path are alternately turned ON / OF according to the recording signal.
A magnetic head drive circuit provided with a switch control circuit that performs a F operation, wherein the auxiliary coils of the first current path and the second current path are both wound around a common magnetic core, and the magnetic flux in the magnetic core is reduced. The heads are wound in the same direction, and the head
A magnetic head drive circuit configured to reverse the current supplied to the magnetic head.